Method and apparatus for tracing metallic bodies in fabrics



Oct. 13, 1931.

J. BING 1,827,349

METHOD AND APPARATUS FOR TRACING METALLIC BODIES IN FABRICS Filed Dec. 11, 1928 If 1&-

fif gfl. 11

Jizyezzfon W VM Patented Oct. 13, 1931 Jones nine, or EISENACH, Gasman-i Assmnon ire man FIRM 1 MAGNET-WEEK JG; MLKHH. SPIEZIMEABRIK Ffi RviELEKTRQMAGNET-$; PPARATE, 0F EISEN 1. msQsMaA mre tsmime META'Ln c BODIES IN-FABRICS I i "ffipplfieation filedlJeeeinher Serjiailil'o/SZEQIGE, and in Germany March 3 1928.

'inventionfre'late's' to an examination of flat-goods; especially of texturesywhich' con sistsin tracing casual metallic bodies, espe'cially needles broken par-ts thereof,- which il'l'flifYi-b a cpidentailly contained in sueh: goods.

inthe"weavers-trade"great 'difihulties arise the {oceurenoe "of i thin nietallic needles in t'hetextlrressinee the said; needles lead tothe tearing 'of thetabric and may also; by

9 rusting, give rise to spots or stains:

3 with magnetic and with mechanical: means;

have alreadybeen made to devise an antomatieap lie/rice tor removing needlesffrom the'webo-f fabric during-the manufacturing process: Such a ttempts haveg'beenmade both but' hitherto without success. It has also already been proposedt'o employ the electrical contaict action' of faneedle in passing-over? rollers fo r tlie givingfof a signal. These attemptshavealso led "to -no -sncc%s; since; if the meedle "is nnfavouraihl'y rpia'ced in the web oi fabric the latter hasitselfian insulating action andthnsprevents the contact eflect.

Myinvention obviates all these diificuiti'esg the'ioliowing manner. 'The' webof fabric tobeexarnined for needles or the like is passed between'lih'etallic .tabric feeding and" giiid i'ngrollersinnctioningalso ashigh piote an electrodes whieh are electrically? insulated {Q from one another, and to each fabricfeeding and g u-iding rollrer an electrical? voltage-is; supplied by means of a suitable 'sme'll higlr voltage transformer. The fabric feeding rollers are placed enclose-together that the cloth 'canjust pass between them-without an eiectric-oontadt'being closed through the said rollers, owing to the insniating action of the intervening fabric. 5

Now, if an electrically conductingforeign body, such as a needle: embedded in fabric, forexamplqxpasses between the fabric feed ing and guiding rollers, theair gap is shortened by the metal of the needie and a slight spark-discharge occurs between'th'e two rollers at 1, he point where the needle-ispassing.

As a result of this, the current conditions of the electric circuit including the correspond ing winding orthe transformer alter in such a way that in the other winding of the trans former the increasing current strength can bra-utilized for'actuating an'automatic elecof I anelay,: for example. i The operator "can t-henieas'ily'remove the needle or the like.

In the drawings an embodiment of my invention consisting in an apparatus for automatically tracing needles and other metallic bodies'in textures is illustrated".

Fi'g fl is 'afschematieview'ei the entireapparatus jwrith a-wiring diagram of the eleotric partbif the apparatus, the rollers for feedin the texture to be examined being only partly-shown and the clutch for controlling the'drive of the rollers being partly shown in side *elev ation' and partly in a longitudinal sectionx Fi g. 2 is aside elevation of a pair ctrollersdMfeeding the texture to be examined! 1 lg 2' aretwo cooperating feed rollers the surfaces-of which consist of a metal or another material conducting electricity. The length of'the said rollers "corresponds with the breadth of the texture 3 to be examined, whilst the gap between the cooperating-superimposed rollers corresponds vvith-thethickmess: of the said texture. The rollers are mounted in bearings 4, one of which is shown in Fig. 1. The rollers are mounted in such a way'that the two rollers are electrically insulated from each other. For this purpose the hea'rings'of the upper roller 1 may be mounted in the respectire platform with the application of an intermediate bushing 5 of insulated material.

The lower'roller 2 may be rotated from any source of energy, 'and according to theembodiinent of the invention illustrated in the drawing the said roller is driven through the intermediary of an electrom'agnetically actuated friction clutch 6 which substantially consists of three parts, the magnet body 8, being fixed on the driving shaft 7 of the roller 2 and encasing the exciting coil 9, the armature disc 10 cooperating with the magnet body and being loose on the shaft 7 and the pulley 11 which is non-rotatably mounted on the armature disc and driven by a belt 12.

The exciting current is fed from the circuit 14 to the exciting coil 9 by means of slip rings The primary or low-voltage coil 23 of the said transformer lies in an alternating current circuit 25 which alsocontains the coil: 26 of a relay 27 an'd -isfed' from asour'ce 2 15" 28 is the armature of this relay, and a spring 29 tends to movesaid armature away from the magnet core 30 0f the relay.

which is normally in touch with two contacts 32 of a circuit33 whichaincludes the source of -current 34suand-the ,coil 3510f 'a second relay 36, the armature 3.7- of which is'provided' With a contact 38'throu'gh which short'circuit Es produced'between the .two contacts'16 men-.

tioned above.

The operating of; the apparatus is asfollows: According-to Fig. 1the-circuitf14' ins cluding the exciting coil 9 ofthe clutch 6 is' closed by-the armature 37- ofthere'la-y '35. In consequence-thereof the. clutch 6-is en-' gagedso that the pulley ll is fixed to the shaft 7 and the roller 2 is rotated. 'T-he texture 3 to be examined is now fed through the gap between the said roller2 and theupper roller 1 and taken along by'theroller 2 whereby the surfaces of the rollers are in close contact with both sides'of the texture..-

If now the fabric contains a needleiorzthelike which may project on-the one or thei'other side of the fabric or -be fully embedded in the, texture, and the said needle passes the rollers 1,2, the electrical'conditions in the circuit including the rollers '1, 2 as'electrodes andthe secondary coil 21 of thetransformer are altered. 1

. Normally the said alteration willresult in an electric discharge. which in accordance with the position of the foreign. metallic body relative to the rollers 1. 2 will take place-between the foreign body and one of the rollers or between the foreign body and both-of the rollers.

On the primary side of the transformer 22 the alteration generally results in a strengthening of the current in the circuit 25. In consequence thereof the armature of the re lay 27 is attracted against the action of the spring 29. Thereby the circuit 33 is inter rupted on the contacts 32, and the relay 36 correspondingly switched off so that the armature 37 of said relay moves downward and interrupts the circuit 14 whereby the electromagnetic clutch is switched out. The drive of the roller 2 is now interrupted and the fabric stopped so that the foreign body may easily be removed from the fabric.

The energy of the small spark discharge that occurs is kept so small, preferably by i the use of small transformers, that it is not sufiicient to produce any visible efiect on the cloth. Experiments have shown that this apparatus is exceedingly sensitive and operates in an absolutely reliable manner. t makes, the machine entirely independent of the; attention of the operator. since it ;-'stops the machine automatically whenever such disturbing needles or the like occur in the fabric."i" 2 For'the-inventive idea it"is'a matter of indifference whether the high voltage is produced as indicated in the accompanying draw- 'byan alternating current transformer or On thearmature 28 a contact 31 is provided apparatus serve by diminishingthe air gap-- to produce an alteration of the electric con-v ditions of the controlling circuit.

Insteadof the two rollers, plane surfacesmay be employed.-between which the web of fabric, passes.

natively, one roller might co-operate with one plane surface.

I claim:

1.-'An apparatus for automatically searching for metallic bodies such as needles in textile fabrics, comprising anv electric circuit, electrodes in saidcircuit, one of said electrodesforming a driven roller adapted to convey the fabric to be examined, an electric transformer having a high voltage winding and a low voltage winding,the high voltage winding being inclosed in thesaid electric circuit, aneIectromag'netic clutch adapted to interrupt the rotation of the said roller and an electric relay in the said low voltage winding'adapted to disengage the said clutch.

2.: Apparatus for automatically searching for metallic needles in textile fabrics. comprising an electric circuit. two rollers electri'cal-lv insulated from each otherand spaced apart from each other so asto be able to receive the fabric to be controlled between them, means for rotating said rollers, an electric transformer. having a high voltage and a low voltage winding. an electric circuit inclosing said rollers and said high voltage winding, a clutch adapted to stop said rotating means. and an electric relay inserted in said low voltage winding and adapted to disengage said clutch.

. 3. In an apparatus for detecting metal particles in non-metallic material, an electric circuit including a high tension current source and two electrodes between which the material to be examined is passed, and means responsive to changes in the electric conditions of said condenser.

4. In an apparatus for automatically tracing metallic foreign bodies in fabrics or the like, an electric circuit including two metallic rollers normally electrically insulated from each other, means for feeding said fabric be- This detail is immaterial sofar .as Ithe invention is concerned. Alten tween said rollers, said feeding means being normally operative while the fabric is passing between said rollers, means responsive to discharges of said circuit due to foreign bod ies in the fabric, said responsive means controlling said feeding means and wherein said rollers form the feeding means for said fabric.

5. A method of automatically tracing casual metallic bodies embedded in fabrics which consists in passing fabric in fabric feeding and guiding contact between fabric feeding and guiding high potential roller electrodes contained in a high tension electric circuit and in utilizing for the controlling of the fabric movement the alterations of the electric conditions of said circuit due to the presence of an embedded metallic body in that portion of fabric between said high potential roller electrodes.

6. A method of automatically tracing casual metallic bodies embedded in fabrics, which consists in passing fabrics in fabric feeding and guiding contact between fabric feeding and guiding high potential electrodes contained in a high tension electric circuit, and in utilizing for the control of the said feeding electrodes, spark discharges as metallic bodies embedded in said fabrics pass between said fabric feeding high potential electrodes.

7. In apparatus for tracing casual metallic bodies embedded in fabrics comprising a high tension electric-circuit, fabric-feeding and guiding high potential electrodes in said circuit, said fabric being in fabric feeding and guiding contact with each of said electrodes, said electrodes being insulated each from the other, and means for stopping the feed of said fabric when a metallic body embedded in said fabric is present between said high potential electrodes.

8. In apparatus for tracing or searching out casual metallic bodies embedded in finished fabrics, means for feeding said fabrics, a high tension electric circuit, high potential electrodes in said circuit, said fabric being normally in contact with each of said electrodes; and means for stopping the feeding of said fabrics, when a metallic body is found in said fabric between the said electrodes.

9. An apparatus for tracing or searching out extraneous metallic bodies, embedded in fabrics; electric circuits; fabric feeding high potential electrode roller devices operatively included in said circuits; and means for stopping the mechanical operation of the said fabric feeding high potential electrode roller devices zlirough the presence of an embedded metallic body in the fabric between said electrodes.

10. In an apparatus for feeding and examining fabrics and other strip material for the presence of extraneous metallic bodies, insulated high potential electrodes arranged in constant contact with the opposite side 

